Sensing products are used in a variety of camera arrangements, including backside illumination sensors, and are sometimes used in low light environments. Several sensing products rely on passing light through a semiconductor layer for sensing incident light. The semiconductor layer is thin enough to allow light to propagate, however, some techniques of layer thinning create a semiconductor layer having a significant thickness variation across the layer. Variations in the layer's thickness result in uneven propagation of light through the semiconductor layer, which in turn prevents the sensor from collecting accurate data resulting in decreased image clarity.
A total thickness variation of the light incident surface for the sensing product resulting from some techniques produces image distortion in an image captured by the sensing product. Some techniques create a total thickness variation of a light incident surface of 0.20 μm or greater. As the total thickness variation increases, the amount of image distortion increases.